Comparison between the effect of static contraction and tendon stretch on the discharge of group III and IV muscle afferents
Comparison between the effect of static contraction and tendon stretch on the discharge of group III and IV muscle afferents
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DOI：
10.1152/japplphysiol.00629.2005
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发表时间：
2005-11-01
影响因子：
3.3
通讯作者：
Kaufman, MP
中科院分区：
文献类型：
--
作者：
Hayes, SG;Kindig, AE;Kaufman, MP
运动压力反射是由机械刺激和代谢刺激引起的。肌腱拉伸不增加肌肉代谢，因此用于研究运动压力反射的机械成分。使用肌腱拉伸来研究运动压力反射的机械成分的一个重要假设是，拉伸与静态收缩刺激相同的III组机械敏感肌传入神经。我们通过比较III组和IV组肌肉传入神经对肌腱拉伸和静态收缩的反应，在失脑猫身上测试了这一假设的准确性。两种演习的紧张时间指标和峰值紧张发展没有显著差异。我们发现三头肌表面肌肉的静态收缩刺激了30个III组传入神经中的18个和11个IV组传入神经中的8个。同样，肌腱拉伸刺激了30个III组传入神经中的14个和11个IV组传入神经中的3个。然而，在18个对静态收缩有反应的III组传入神经和14个对肌腱拉伸有反应的III组传入神经中，只有7个对两种刺激都有反应。平均而言，响应静态收缩的18个III组传入神经的传导速度（11.6 +/- 1.6 m/s）明显低于响应肌腱拉伸的14个III组传入神经的传导速度（16.7 +/- 1.5 m/s） （P = 0.03）。我们的结论是，与静态收缩相比，肌腱拉伸刺激了不同的III组机械敏感肌传入神经群。虽然在两类III类机械敏感传入神经之间有一些重叠，但并不大，占响应静态收缩的III类传入神经的不到一半。
The exercise pressor reflex is evoked by both mechanical and metabolic stimuli. Tendon stretch does not increase muscle metabolism and therefore is used to investigate the mechanical component of the exercise pressor reflex. An important assumption underlying the use of tendon stretch to study the mechanical component of the exercise pressor reflex is that stretch stimulates the same group III mechanosensitive muscle afferents as does static contraction. We have tested the veracity of this assumption in decerebrated cats by comparing the responses of group III and IV muscle afferents to tendon stretch with those to static contraction. The tension-time indexes as well as the peak tension development for both maneuvers did not significantly differ. We found that static contraction of the triceps surae muscles stimulated 18 of 30 group III afferents and 8 of 11 group IV afferents. Similarly, tendon stretch stimulated 14 of 30 group III afferents and 3 of 11 group IV afferents. However, of the 18 group III afferents that responded to static contraction and the 14 group III afferents that responded to tendon stretch, only 7 responded to both stimuli. On average, the conduction velocities of the 18 group III afferents that responded to static contraction (11.6 +/- 1.6 m/s) were significantly slower (P = 0.03) than those of the 14 group III afferents that responded to tendon stretch (16.7 +/- 1.5 m/s). We have concluded that tendon stretch stimulated a different population of group III mechanosensitive muscle afferents than did static contraction. Although there is some overlap between the two populations of group III mechanosensitive afferents, it is not large, comprising less than half of the group III afferents responding to static contraction.